Heat exchange unit



July 28, 1953 W. RASKIN HEAT EXCHANGE UNIT Filed June 1'7, 1950 FIG I Q- 12 E I o INVENTOR WALTER P-A$K\N GTT ORNEY Patented July 28, 1953 UNITED STATES PATENT OFFICE HEAT EXCHANGE UNIT Walter Raskin, Brooklyn, N. Y.

Application June 17, 1950, Serial No. 168,831

2 Claims. (01. 257-256) This invention relates to heat exchange plates and units, and particularly to metal plates provided with one or more fluid carrying tubes permanently secured thereto in heat exchange relation between said plates and tubes.

The main object of my invention is to provide generally fiat means serving as a heating or cooling plate which maybe used alone or in multiples to form heat exchange units for various purposes, the resulting units being heated or cooled by means of heating or cooling fluid propelled through portions thereof forming part of the structure thereof.

Another object is to make such heat exchange plates or units of sheet metal and attach fluid heating or cooling tubes thereto without using staples, rivets or the like, nor resorting to welding, brazing or soldering to secure the tubes in position.

An ancillary object is to form the metal plates in such fashion as to partly envelop the heating or cooling tubes and thereby provide intimate metallic contact between the sheet metal and the tubes for efiicient heat transfer betweenthem.

It is also an object of my invention to attach several heating and cooling tubes to a single metal sheet or plate in such manner that the ends of these tubes extend beyond the ends of the plate involved for the purpose of providing connections between the tubes outside the area of the plate to which the tubes are attached.

Yet another object is to mount several plates or sheets provided with the heating and cooling tubes upon a relatively larger plate and interconnect the tubes upon the plates thus mounted in order to build up a heat exchange unit of large area.

It is even an object of this invention to employ a certain effective method of making the individual plate units to provide them with the heat exchange tubes in permanent association therewith.

Another material object is to make the individual heat exchange units of plates of such metals or alloys as will conduct heat most effectively, among which may be mentioned copper and aluminum and its alloys.

Other objects and advantages of the invention will be brought out more fully in detail as the specification proceeds.

In order to facilitate ready comprehension of this invention for a proper appreciation of the salient features thereof, the invention is illustrated on the accompanying drawing forming part hereof, and in which:

Figure 1 is an elevation of a heat exchange unit made according to the basic principles of my invention and embodies the latter in a practical form;

Figure 2 is a vertical section of the same unit as taken on line 2-2 in Figure 1;

Figure 3 is an elevation of a heat exchange assembly formed by building up a complete heat exchange unit of large efiective area from a plurality of units such as are shown in Figures 1 and 2; and

Figure 4 is a fragmentary vertical section of the assembly of Figure 3 as taken on line 4-4 in that figure.

Throughout the views, the same reference numerals indicate the same or like parts.

Many forms of construction have been resorted to for transferring heat and cold from heating and cooling fluids in pipes and tubes, the latter frequently being suspended in more or less parallel spaced apart lengths and loops at the sides rear and top portions of boxes, cabinets and the like for heating or cooling these types of containers in conventional manner, and such tubes have even been attached directly to metal walls in the cabinets or containers involved by soldering, brazing or riveting or other means. All too often, it has been found that the heat exchange efliciency has been rather low, requiring the use of considerable lengths of space wasting pipes, tubes and coils, not to mention that in many cases, it has been difiicult to standardize such make-shift heat exchange installations. Of course, great difiiculty has likewise been encountered when such heat exchange systems required repairs and replacements. As though these disadvantages were not sufiicient to render the original cost and the upkeep of conventional heat exchange devices and systems much higher than they should be, the matter of corrosion has often introduced a serious difficulty into this field, because leakage of smelly and even poisonous fluids and gases have occurred in such fashion that the leaks were almost impossible to reach and fix, so the whole system involved would likely be condemned and required total replacement.

Upon considering these difiiculties and conventional drawbacks in heat exchange structures generally, it has occurred to me that such systems should be broken up into small similar standardized units in which the tubes for the heating and cooling fluids should be largely in contact with a plate forming the main member of the unit and should also be accessible at the ends thereof, and the units so designed that two or more are readily mounted on a relatively larger plate to form an assembly of selected size. As a result of such consideration, I have succeeded in evolving a heat exchange unit and assembly system capable of being standardized and having several advantages while fulfilling the foregoing objects, as will now be more fully set forth.

Hence, in the practice of my invention, and referring again to the drawing, a sheet or plate of preferably malleable metal forming a good heat conductor such as copper or aluminum is shown at [0, being for practical purposes rectangular in outline, is formed with a plurality of substantially parallel grooves H, II, etc., extending from one end to the other. The mentioned grooves l l are undercut in form, so that the plate upon one side l2 merely presents the grooves as narrow slits, While on the other or rear side l3, the convex sides of the grooves appear as almost tubular projections Hi, It thereon.

These tubular groove projections are of sufficiently deep character and form to house and largely envelop individual lengths of a fluid conducting tube i5 also made of copper, aluminum or like malleable metal of high heat conducting capacity, the grooves fitting the tube portions therein so snugly that the metal of the plate is in close gripping contact with the tube throughout the length of each groove. Externally of the edges of the plate ill, the pipe or tube i5 is formed into several connecting loops l6, if), H, while at the two extremities, the tube terminates in threaded ends l8, 13. The tube is thus a sinuous and continuous conduit from, one threaded end ii! to the other threaded end i9, with the straight portions of this tube embedded in plate It and the looped connecting portions i6 and H extending into accessible positions outside the area of the plate. Thus far, the basic heat exchange unit has been described which merely requires to be repeated and connected together to form complete heat exchange units of various sizes and capacities while retaining the advantages of being accessible and standard in form. For such assembly purposes, a large and relatively heavier plate 23 is formed with a group of open areas or windows 2!, 21, etc., separated by a pair of narrow strips 22, 22 integral with plate and disposed horizontally, and relatively wider upright plate sections 23, 23 forming the intermediate portion of the plate. About the periphery of this plate, a reinforcing edge 24 is formed to stiffen the same and also generally protect the units mounted on the plate, as about to be explained.

In the example of a heat exchange unit assembly shown, four plates l0, l6, etc., provided with the grooves ll housing the lengths of each tube .l 5, are turned with their flat sides l2 facing plate 20 within reinforcing edge 2 in such position that in each case the plate to of the unit involved covers a window or opening 2|. The edges of the plates H] are secured to the edges of these openings and the strips 22 and intermediate portions 23, 23 by screws or rivets 25, 25 so that the projecting portions l4, M of the grooves and the tubes l5 all extend into the chamber formed upon assembly plate 20 by its peripheral bounding wall 24.

In order to interconnect the units A, B, C and D, as they may be noted for convenience, the units A and B are disposed in such position that their threaded ends l8, l9 on tubes l5 are directed toward units C and D, while in the case of these latter units, the threaded ends [8 and [9 on their tubes I5 are directed toward units A and B. The

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upper threaded ends l8, [8 of units A and C are connected together by a short tubular connector 26 with internally threaded enlarged ends 27, 21 screwed on tube ends 18, being of more or less conventional character.

The lower threaded tube ends l9, I9 of units A and C are connected to the upper tube ends [8, l8 of units B and D by means of the two looped connecting tubes 28, 28 provided with the internally threaded enlarged ends or nuts 29, 29 which are screwed on the tubes and connecting the upper units with the lower. To the lower threaded ends I9, E9 of tubes 15 of units B and D are connected the ends 30, 3| of tubes supplying the heating of cooling fluid to the heat exchange assembly, the nuts 32, 32 serving to connect these supply tubes to the mentioned unit tube ends l9, 19. The four units are thus interconnected to receive a circulated supply of heating or cooling fluid through pipes or tubes 15, I5 thereof, while each unit is accessible for repairs or replacement of the unit involved without the necessity of removing the rest.

With the individual units thus secured to assembly plate 20 and the tubes connected as described, the entire assembly becomes an effective heat exchange unit of practical size and capacity to form the inner wall, top or back within a cabinet serving to freeze or cool food articles, for example, or for any other heat exchange purpose.

It has already been mentioned that the metal used for the unit plates l0, I0 is preferably copper or aluminum, although any other metal or alloy may be used. Copper and aluminum are not only good heat conductors, but are also malleable, this characteristic being desirable during formation of each plate [0 to fit the straight sections of tube l5. This may be done in two or more ways.

First, the plate I0 is deeply grooved. or folded to receive tube l5 along its straight sections, after which the intermediate portions 33, 33, etc., are pressed down flat so that the edges 34, 36 resulting therefrom tend to close in upon tube l5 and partly envelop the same so that this tube is virtually gripped in an undercut groove, formed from each fold 14.

Another method of thus enfolding the sections of tube [5 in the plate is performed by first impressing deep grooves into which the sections of the tube are inserted, then the intermediate portions 33, 33 are forced together so as to approach each other and thereby bring their edge 34, 34 closer together, with the result that the tube is enclosed virtually in three quarter tubes integral with plate In in each case, the tube l5 being therefore in most direct and intimate contact with the plate so that heat exchange occurs readily from the tube to the plate for heating or refrigeration.

While four units have been shown and described as associated on an assembly plate, two, three or any other number of units can thus be mounted and interconnected, as desired.

Manifestly, variations may be resorted to, and parts and features may be modified or used without others, within the scope of the appended claims.

Having now fully described my invention, I claim:

1. A heat exchange assembly unit comprising an assembly plate having a plurality of spaced and independent apertures, a plurality of tubesupporting plates secured to the assembly plate and individually covering the apertures therein, each of the tube-supporting plates having a plurality of spaced, parallel deep grooves having their open sides facing the respective aperture covered by said tube-supporting plate, a heating and cooling tube having a plurality of straight tube sections located in the grooves in each tubesupporting plate, curved integral connections located beyond the ends of the tube-supporting plates and connecting the tube sections, connections between the tubes of the several tube-supporting plates, said connections being also located beyond the ends of said plates, connections to the extreme ends of said tubes for supplying heating or cooling fluid to the tubes of the various tube-supporting plates, the curved end connections and all other connections being located beyond the apertures and overlying a face of the assembly plate, and a protective flange on the assembly plate extending beyond the tubes and the grooves in which said tubes are positioned.

2. A heat exchange assembly unit comprising, an assembly plate provided with an opening, a tube-supporting plate larger than the opening fitted over the opening and secured to the as sembly plate, the tube-supporting plate having a plurality of spaced, parallel, deep grooves having their open sides facing the opening, a heating and cooling tube having a plurality of straight tube sections located in the grooves in the tubesupporting plate, curved integral connections located beyond the ends of the tube-supporting plate and connecting the straight tube sections, connections to the ends of the tubes for supplying heating or cooling fluid to the tubes, the straight portions only of the tubes being exposed through the opening in the assembly plate, with the curved end connections overlying a face of the assembly plate adjacent to said opening, the assembly plate being flanged about its edge.

WALTER RASKIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 473,176 Holden Apr. 19, 1892 1,880,877 Dick Oct. 4, 1932 1,888,900 Austen Nov. 22, 1932 2,205,984 Kromas June 25, 1940 2,281,299 Steenstrup Apr. 28, 1942 2,306,526 Dalzell et a1. Dec. 29, 1942 2,441,463 Achs May 11, 1948 2,524,655 Dunlap Oct. 3, 1950 

